Mounting of a flywheel of a clutch, supporting the rotor of a rotating electric machine, on the crankshaft of a vehicle engine

ABSTRACT

The assembly is characterised in that the casing ( 62 ) of the engine of the motor vehicle carries, fastened to it, an axially projecting sleeve ( 246 ), in that the crankshaft ( 11 ) is lengthened axially by an extension ( 111 ), which firstly penetrates into the interior of the sleeve ( 246 ), and secondly serves for fastening the flywheel ( 13 ) of the clutch, and in that a bearing means ( 346 ) is interposed radially between the extension ( 111 ) and the sleeve ( 246 ), being located radially inwards of the rotor ( 6 ).

FIELD OF THE INVENTION

The present invention relates to an assembly of a flywheel of a clutch,carrying the rotor of a rotary electrical machine, on the crankshaft ofan internal combustion engine of a motor vehicle, as described in thedocument FR-A-2 782 355 (WO00/06897).

PRIOR ART

It is seen in FIG. 1 of the above mentioned document that the flywheelof the clutch carries at its rear end the reaction plate of a frictionclutch, and has a sleeve which extends towards the casing of theinternal combustion engine, referred to as the engine, of the motorvehicle. The sleeve carries the rotor of a rotary electrical machine,which is thereby incorporated in the clutch. This machine comprises, inthe known way, a fixed stator surrounding the rotor, with an airgapbetween the inner periphery of the stator and the outer periphery of therotor.

The front end of the sleeve, which is also the front end of theflywheel, is fixed on the crankshaft of the engine.

The rotor has a significant weight, and, like the reaction plate and theclutch, it is cantilevered from the front end of the sleeve.

As is known, the crankshaft vibrates when the engine of the vehicle isworking.

This gives rise to troublesome dynamic knocking effects in the region ofthe airgap between the stator and rotor, so that the airgap can vary andhas to be dimensioned accordingly, which is detrimental to theperformance of the machine. In addition, because of the cantilevers,inertias and weights of the rotor and clutch, the crankshaft and itsbearings are subjected to strong applied forces, which is detrimental tothe mechanical strength and useful life of the crankshaft.

In the embodiment of FIG. 4 in the document FR-A-2 782 355, a constantairgap is obtained by use of a carrier member.

Although that solution is satisfactory, the carrier member increasesoverall size. In addition, it calls for the use of a ball bearing oflarge size, interposed radially between the carrier member and theflywheel. The same is true in the embodiment in FIG. 1 of the documentU.S. Pat. No. 6,253,437.

OBJECT OF THE INVENTION

The object of the present invention is to overcome these disadvantagesin a simple and inexpensive way.

It is therefore an object of the invention to obtain an independentairgap which is insensitive to all disturbances linked to operation ofthe internal combustion engine of the vehicle, such as vibrations,dynamic knocking, and play, while protecting the crankshaft, and inparticular the bearings of the latter.

According to the invention, an assembly of a flywheel of a clutch,carrying the rotor of a rotary electrical machine, on the crankshaft ofan internal combustion engine of a motor vehicle, of the kind mentionedabove, is characterised in that the casing of the engine of the motorvehicle carries, fastened to it, an axially projecting sleeve, in thatthe crankshaft is lengthened axially by an extension, which firstlypenetrates into the interior of the sleeve, and secondly serves forfastening the flywheel of the clutch, and in that a bearing means isinterposed radially between the extension and the sleeve, being locatedradially inwards of the rotor.

Thanks to the invention, the extension and the sleeve are fittedcoaxially, so that through the operation of the bearing means, the fixedsleeve is a sleeve which takes up applied forces, and which penetratesinto the central aperture of the rotor.

The extended crankshaft is therefore well supported, and the airgap isinsensitive to the disturbances resulting from operation of the engineof the motor vehicle. It will be appreciated that the airgap is constantand is reduced even further, because the flywheel, being fixed on theextension supported by the bearing means, is also less sensitive todisturbances resulting from operation of the engine of the motorvehicle. The performance of the machine is therefore improved.

The crankshaft bearings are protected because of the presence of thesupplementary bearing means.

In addition, the assembly is simplified because the sleeve is simpler inform than the carrier member which, in the document U.S. Pat. No.6,253,437, constitutes a spacer between the casing of the engine and thecover of the clutch.

In one embodiment, one of the crankshaft bearings is omitted and isreplaced by the bearing means according to the invention, which isfitted in line with the rotor, that is to say directly below the rotor.For this purpose, the sleeve penetrates, with axial and radialclearances, into a cavity of the flywheel which is delimited firstly bya first portion having an axially oriented surface for mounting therotor thereon, and secondly by a second portion for fastening theflywheel on the extension.

The solution enables the dimensions between the casing of the engine andthe reaction plate to be reduced without detriment to the performance ofthe machine.

In addition, the radial dimension of the bearing means is small, becauseit is in contact with the extension of the crankshaft. It is thereforeinexpensive. This bearing means can have whatever axial length isdesired.

Omission of the carrier member of the prior art makes the solutioninexpensive. In addition, no additional machining of the flywheel isnecessary.

The reduction in overall size enables the friction clutch to be fittedwith a wear take-up device that compensates for wear in the frictionliners and maintains the clutch engaging means of the clutch, such as adiaphragm, always in the same position when the clutch is engaged (withthe friction liners gripped between the pressure and reaction plates ofthe clutch). It is possible to give the clutch other functions.

Similarly, it is possible, because of the absence of the carrier member,to increase the axial thicknesses of the rotor and stator, givingimproved performance for the machine.

Markers or targets are conventionally provided for measuring the speedof rotation of the engine and for adjusting the ignition of the engine.These markers are for example carried by the flywheel, and in particularby the reaction plate. This gives improved accuracy of the measurementsbecause the flywheel is also insensitive to the disturbances set up bythe engine.

In another version, the bearing means consists of a ballbearing with,either, one row or two rows of balls.

In a further version, in order to reduce the diametral size of thebearing means and sleeve, as well as the radial size of the machine, thebearing means consists of a needle bearing, or, preferably, a cushionmember or, in general terms, a plain bearing, which is made for exampleof reinforced and/or lubricated plastics material, this being lessexpensive.

Preferably, the bearing means is lubricated, and in one embodiment itconsists of a cushion member lubricated by the engine oil of thevehicle.

In this case, the load bearing sleeve has at least one passage forreturn of oil to the casing, and the crankshaft has delivery passagesfor supplying the cushion member with oil.

A seal, such as a lip seal, is then interposed between the innerperiphery of the sleeve and the outer periphery of the extension.

The said extension has, at the level of the bearing means, a radiallyprojecting local portion, the largest diameter of which enables theclutch flywheel also to be fixed.

In one embodiment, the projecting portion constitutes the free end ofthe crankshaft and has a nose for centring the clutch flywheel.

In one embodiment, the first part of the flywheel consists of an axiallyoriented sleeve and the second part is a transversely oriented annularring.

In a further version, of course, the sleeve is of ribbed form. The firstpart is not necessarily in the form of a sleeve because radial space issaved.

BRIEF DESCRIPTION OF THE DRAWINGS

The attached description illustrates the invention with reference to theattached drawings, in which:

FIG. 1 is a view in axial cross section of the assembly according to theinvention;

FIG. 2 is a scrap view on an enlarged scale of the central part of FIG.1;

FIG. 3 is a view in the direction of the arrow 3 in FIG. 1, but withoutthe motor casing, without the crankshaft and without the sleeve.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the drawings, those elements which are common with those in thedocument FR-A-2 782 355 will be given the same reference signs, so thatreference can be made to that document for more details. Thus, in FIG.1, an apparatus for stopping and starting an internal combustion engineof a motor vehicle is shown at 1.

The apparatus 1 is interposed axially between the engine of the vehicleand the motion transmission unit, such as a manual or automatic gearboxof the motor vehicle. In this example, the transmission unit is agearbox having a casing which includes at the front hollow portionswhich, in particular, constitute a clutch cover 14 and a passage for atransmission shaft 6501 between the wheels of the vehicle. The shaft6501 is located close to the clutch cover 14.

The apparatus 1 includes a friction clutch 3 and a rotary electricalmachine 2 which in the present case is of a synchronous type. Thismachine includes a stator 5 surrounding a rotor 6. The stator and rotorhave, in the known way, a body or core in the form of a stack oflaminations. The body of the rotor is configured for the mounting of asquirrel cage 60, while the body of the stator has grooves, which arefor example semi-closed, for mounting electrical conductors whichconstitute the armature windings 8 of the machine. These conductors arethose of conventional windings, wound from wire or consisting of bars,for example U-shaped hairpins, the ends of the branches of which arewelded so as to constitute at least one coil per phase as can be seen inthe document U.S. Pat. No. 2,928,963, or in the document WO92/06527; themachine is of the polyphase type.

The machine is for example of the three-phase type, with the windingsstar-connected. In another version and as explained in the document U.S.Pat. No. 2,928,963, the number of phases is more than three.

In all cases, the conductive wires or conductive hairpins extend throughthe body of the stator within grooves in the latter, and extend to theoutside of the stator body so as to constitute a first and a secondchignon, projecting axially in the known way.

The friction clutch 3 includes a reaction plate 4 of mouldable material,which is a casting in this case and which is part of an annular drivingflywheel 13 which constitutes the flywheel of the clutch and which, inaccordance with one feature of the invention, has a simplified form ascompared with that in the document FR-A-2 782 355.

The stator 5 of the rotary electrical machine is carried internally by aspacer 61 which has an internal cooling chamber 6002 for circulation ofa heat transfer fluid, such as the coolant liquid for the engine of thevehicle, whereby to evacuate heat and cool the stator.

This spacer 61 is fitted at the outer periphery of the cover 14, and isinterposed axially between the casing 62 of the engine of the motorvehicle and the clutch cover 14 which is fixed to the motiontransmission unit, the input shaft, which constitutes a driven shaft,being seen at 12. The engine has a driving shaft in the form of acrankshaft, the output end portion of which consists of a shaft 11. Thisoutput end portion will simply be referred to as a shaft. The axial axisof symmetry of the shaft 11 is aligned with that of the shaft 12, so asto define an axial axis of symmetry X-X which is the axis of rotation ofthe shafts 11, 12 of the clutch 3 and of the rotor 6, as is describedbelow.

The cover 14 surrounds the reaction plate 4. Screws 64 secure the spacer61 and clutch cover to the casing 62 of the engine of the vehicle. Thesescrews have a head which bears on a radial flange formed on the free endof the cover 14. The screws extend through the flange of the cover andthe spacer, to be screwed into threaded bores in the casing 62 and sosecure the spacer. The cooling chamber 6002 of the spacer 61 is in theform of a channel within which a heat transfer fluid flows, in themanner described in the embodiment of FIG. 14 in the document FR-A-2 782355, reference to which is invited.

In accordance with a feature (FIG. 3), the inlet and outlet ducts 6008for the heat transfer fluid are disposed at the circumferential ends ofan opening 6500 for permitting passage of the transmission shaft 6501between the wheels of the motor vehicle, so that the spacer is open atthis point.

The opening 6500 has a contour in the form of an arc of a circle. Anyother form may of course be envisaged; the spacer is recessed at thispoint. This arrangement enables the outer diameter of the stator 5 to beincreased by local interruption of the chamber 6002 at this point; theducts 6008 are disposed on either side of the opening 6500.

The spacer 61, stator 5 and rotor 6 are annular in form and are mountedcoaxially with each other.

There is a precise and constant airgap 7 between the inner periphery ofthe stator 5 and the outer periphery of the rotor 6, which is carried bythe flywheel 13 so that the rotary electrical machine 2 is incorporatedin the friction clutch 3.

The machine 2 is interposed between the casing 62 of the engine of thevehicle and the reaction plate 4.

The flywheel 13 includes a first part in the form of an axially orientedsleeve 46 which is directed axially towards the casing 62.

The outer periphery of the sleeve 46 constitutes an axially orientedmounting surface for the rotor 6, which in this case is force-fitted onthe said surface. For this purpose, the outer periphery of the sleeve 46has a shoulder at its axial end furthest from the casing 62 of theengine of the vehicle.

The sleeve 46 is integral with the reaction plate 4, with which it ismoulded integrally.

The flywheel 13 has at its inner periphery a central, transverselyoriented, second part in the form of an annular fastening ring 140,which is formed with holes for the passage of fastening members 245securing the flywheel 13 to the shaft 11 of the crankshaft. The ring 140is joined, through a frusto-conical portion 142, to the inner peripheryof the reaction plate 4, which is thereby offset axially with respect tothe ring 140 in the direction away from the casing 62.

The sleeve 46 is joined to the outer periphery of the sleeve 140, andprojects axially with respect to the ring 140, extending at right anglesto the axis X-X. The sleeve 46 is directed axially towards the casing 62and is joined to the frusto-conical portion 142 in such a way that thereis an axial clearance between the rotor 6 and reaction plate 4. There isof course an axial clearance between the rotor 6 and casing 62.

The clutch flywheel 13 is made in one piece; its parts 140, 142, 4, 46are of moulded form. It will be noted that the flywheel 13 has aconfiguration similar to that of FIG. 4 in the document FR-A-2 782 355.Nevertheless, it will be noted that the sleeve 46 in FIG. 1 of thepresent Application may extend to the vicinity of the casing 62, andthat the inner periphery of the sleeve 46 is not machined. It is thuspossible to increase the axial length of the rotor and stator of themachine, and therefore its power.

In addition, the outer diameter of the sleeve 46 in FIG. 1 is smallerthan the outer diameter of the sleeve in the document mentioned above,so that the diametral size of the machine 2 is reduced.

Moreover, the frusto-conical portion 142 is inclined axially by a lesseramount than in the above mentioned document, so that the axial distancebetween the ring 140 and plate 4 is reduced.

The absence of a carrier member will also be noted, as will that of arolling bearing, of large size and therefore expensive, acting betweenthe carrier member and sleeve 46.

Omission of the carrier member enables the axial dimension between thecasing 62 and plate 4 to be reduced.

The solution is therefore simple and inexpensive, while enabling theaxial and radial dimensions between the casing 62 and reaction plate 4to be reduced, and without detriment to the performance of the machine.

This is achieved by virtue of the mounting of the clutch flywheel 13,carrying the rotor 6, on the shaft 11 of the crankshaft in accordancewith the invention.

More precisely, the shaft 11 is longer in the axial direction, andtherefore has an axial extension 111 extending towards the reactionplate 4. This extension 111 constitutes the free end portion of thecrankshaft of the internal combustion engine of the motor vehicle. Theflywheel 13 is fixed at the end of the extension 111 by means of itsring 140.

The casing 62 carries, fixed to it, a cylindrical sleeve 246 whichextends axially towards the reaction plate 4 and which at least partlysurrounds the extension 111, which in this example is cylindrical. Thesleeve 246 has at its axial end, adjacent to the casing, a transverselyoriented collar portion 247 which extends outwards away from the axisX-X. The collar portion 247 is formed with holes for fastening thesleeve on the casing 62 with the aid of screws 248. In another version,the sleeve 246 is integral with the casing. The same is true of thespacer 61, which may be made integrally with the casing 62 or clutchcover 14.

A bearing means 346 is interposed radially between the inner peripheryof the sleeve 246 and the outer periphery of the extension 111. Thisbearing means 346 is fitted radially within the rotor 6 and sleeve 46.The sleeve penetrates, with radial and axial clearance, into the cavitywhich is delimited by the sleeve 46 and ring 140. The bearing means 346is fitted in line with the rotor 6. The transverse line which passesthrough the centre of gravity of the assembly that consists of the rotor6 and sleeve 46 passes through the bearing means 346. Preferably, in theembodiment shown, the radial plane of symmetry of the rotor 6, extendingat right angles to the axis X-X and passing through the middle of therotor, is coincident with the radial plane of symmetry of the bearingmeans 346.

The invention is accordingly characterised in that the casing 62 of theengine of the motor vehicle carries, fixed to it, an axially projectingsleeve 246, in that the crankshaft 11 is extended axially by anextension 111 which firstly penetrates into the inside of the sleeve 246and secondly serves for fastening the flywheel 13 of the clutch, and inthat a bearing means 346 is interposed radially between the extension111 and the sleeve 246, being fitted radially inside the rotor 6.

Because of these features, an airgap 7 is obtained which is both preciseand as small as possible, as well as improved mechanical strength of thecrankshaft because of the sleeve and the bearing means which is incontact with the extension 111. The performance of the machine 2 isimproved.

The supplementary bearing means 346 provides relief for the crankshaftbearings.

In the embodiment in FIG. 1, the bearing means 346 replaces one of thecrankshaft bearings.

In all cases, it has the required axial length.

In this example, the bearing means 346 is axially shorter than the rotor6.

The extension 111 has a radially projecting local portion 211 at thelevel of the bearing means 346, which in this example is in the form ofa cushion. In the drawings, the portion 211 is cylindrical, and theplain bearing 346 is tubular.

The projecting portion 211 constitutes the free end of the crankshaft11, and has a nose 311 for centring the flywheel 13. The nose 311 iscylindrical. It has an outer diameter which corresponds to the innerdiameter of the ring 140, so that the said peripheries are in intimatecontact for centring the ring 140 by means of the nose 311, the outerdiameter of which is smaller than that of the portion 211. Accordingly,a transverse shoulder is defined for engagement with the ring 140. Thisshoulder is defined by the axial end face of the portion 211.

The flywheel 13 in this example is fixed on the projecting portion 211at the end of the latter, in this example by means of screws 245, theheads of which bear on the central ring 140 of the flywheel. Thethreaded portion of each screw 245 extends through the ring 140, whichis perforated for this purpose, so that each screw is screwed into afemale thread of the portion 211 to secure the ring 140 in contact withthe axial end face of the portion 211. In place of the screws 215, it isof course possible to make use of gudgeon pins or nuts or any otherfastening member.

The cushion member 346 is lubricated by the lubricating oil of theengine of the vehicle, as is best seen in FIG. 2. For this purpose, thecrankshaft 11 has within its thickness a central axial oil passage 447,into which radial passages 448, spaced apart at regular intervals, areopen so as to supply the cushion member 346 with oil from the engine.The passages 447 are open radially at the level of the cushion member346 into the middle part of the latter. The cushion member is mountedinside the sleeve by means of a first increase in diameter formedintegrally in the sleeve at the level of the outer periphery of theportion 211.

The passage 447 is closed off by a closure, not given a referencenumeral. The passages 447, 448 are therefore oil feed passages.

The oil is able to approach the ring 140, so that a seal 249, which inthis example is a lip seal, must be provided. This seal 249 is incontact with the outer periphery of the portion 211, and is in contactwith the inner periphery of the sleeve 246, which for this purpose hasat its free end a second increase in diameter. The sleeve accordinglyhas three internal diameters.

The sleeve 246 also has in its lower part, within its thickness, atleast one axial passage 446 for return of the oil to the oil sump 400.The passage or passages 446 extend axially through the sump so as toterminate, firstly at the level of the seal 249, and secondly in thesump 400 which is situated in the lower part of the engine, with atransverse passage 401 being defined between the casing 62 and thecollar portion 247.

A plate 6600 is fixed on the spacer 61 as can be seen in FIG. 3. Thisplate is located facing the sump so as to protect the rotor and statoragainst splashing.

A locating element is of course provided for the circumferentialmounting of the sleeve and its passage 446 in the correct position (withthe passage 446 in a lower position). For example, the collar portion247 and the sleeve has a hole for receiving a cotter pin carried by thecasing 62.

The machine 2 has several functions. It constitutes a current generatorin the form of an alternator for the power consuming components of thevehicle, and also acts as a starter for the vehicle. It enables theengine of the vehicle to be stopped at red lights and then to berestarted.

All the functions of the machine are described for example in thedocuments FR-A-2 782 355 and WO98/05882, to which reference is invited.

It will be recalled that the output ends of the armature windings 8 areconnected to an electronic command and control module. This module isfor example fitted on the outside of the assembly of the invention, and,as described in the document FR-A-2 782 353, the spacer 61 carries aconnector which is connected, firstly to the outputs of the armaturewinding phases, and, secondly, by means of cables to the electroniccommand and control module.

The friction clutch 3 has the same structure as that described in FIG. 3of the document FR-A-2 782 355, to which reference is invited.

Thus, the clutch is accordingly of the type having a diaphragm 18, 22which bears on a bead of a cover plate 19 fixed to the outer peripheryof the reaction plate. The cover plate has lugs, formed by stamping outand bending, which extend axially through the apertures in thediaphragm, to be bent radially outwards so that they constitute alocating bend for a crown ring which offers a secondary abutment for thediaphragm. A pressure plate 17 is coupled in rotation to the cover plate19 by means of tangential tongues 25 which permit axial movement of thepressure plate 17, which has a passage for engagement of the outerperiphery of the Belleville ring 18 of the diaphragm. A friction disc 20has, at its outer periphery, friction liners 16 which are adapted to begripped between the pressure plate 17 and reaction plate 4, each ofwhich has for this purpose a friction face for the liner 16 concerned.The liners 16 are fixed to a support which is connected, rigidly or,preferably, elastically, through a torsion damper, to a hub 15 which issplined internally for coupling it in rotation with the shaft 12, whichhas splines complementary to those on the hub 15.

The clutch is therefore normally engaged, so that the torque istransmitted between the shafts 11 and 12. In order to disengage theclutch, pressure is exerted on the inner ends of the fingers 22 of thediaphragm, in this case by pushing with the aid of a clutch releasebearing 24, so as to cause the diaphragm to pivot about the crown ringand thereby cause the action of the Belleville ring 18 of the diaphragmon the plate to cease, so releasing the liners 16 and disengaging theclutch 3. In this position, the torque is no longer transmitted from theshaft 11 to the shaft 12. The clutch is therefore a stopping andstarting device.

The clutch release bearing 24 is of the hydraulically controlled type,concentric with the shaft 12; the hydraulic control includes a guidetube fixed to the base of the cover and serving as a guide for a pistoncarrying a ball bearing, one of the rings of which is arranged to act onthe fingers 22.

In another version, it may of course be controlled electronically or bymeans of a declutching fork. The other versions which are described inthe document FR-A-2 782 355 can also be envisaged. The same is true asregards the electrical machine 2.

It will be noted that the reaction plate 4 has at its outer periphery anaxially oriented annular flange surrounding the reaction plate 17 andhaving a toothed target or marker element for measuring the speed ofrotation of the engine by means of a sensor.

The said flange is joined, through a transverse annular shoulder, to anaxially oriented, annular, second shoulder which surrounds the liners 16and is joined to the outer periphery of the reaction plate 4. Theshoulder serves for fastening of an adjacent component of the stator 5,and serving as an ignition marker for use in adjusting the ignition ofthe engine of the vehicle. FIG. 1 shows the sensors associated withthese markers, reading of which is precise thanks to the invention, sorendering the flywheel insensitive to disturbances caused by theoperation of the engine of the vehicle.

In the drawings, the extension 111 is integral with the crankshaft. Inanother version, it is carried at the end of the crankshaft, for exampleby screwed attachment. The same is true for the sleeve 46, which inanother version is secured by screwing or riveting on the flywheel.

It will be appreciated that the crankshaft, because of the fitting ofthe bearing means 346, is better protected than in a solution of thekind described in the document EP-0 302 118, because, firstly, thebearing means 246 is closer to the engine flywheel, and, secondly, asleeve 246 is provided for absorbing forces. Cantilevers are reduced.

1. An assembly of a flywheel (13) of a clutch (3), carrying the rotor(6) of a rotary electrical machine (2), on the crankshaft (11) of aninternal combustion engine of a motor vehicle, the engine having acasing (62), characterised in that the casing (62) of the engine of themotor vehicle carries, fastened to it, an axially projecting sleeve(246), in that the crankshaft (11) is lengthened axially by an extension(111), which firstly penetrates into the interior of the sleeve (246),and secondly serves for fastening the flywheel (13) of the clutch, andin that a bearing means (346) is interposed radially between theextension (111) and the sleeve (246), being located radially inwards ofthe rotor (6).
 2. An assembly according to claim 1, characterised inthat the bearing means (346) is lubricated.
 3. An assembly according toclaim 1, characterised in that the bearing means (346) consist of aballbearing with, either, one row or two rows of balls.
 4. An assemblyaccording to claim 1, characterised in that the bearing means (346) is aplain bearing.
 5. An assembly according to claim 4, characterised inthat the plain bearing consists of a cushion member lubricated by theengine oil of the motor vehicle.
 6. An assembly according to claim 5,characterised in that the crankshaft (11) has inlet passages (447, 448),and the sleeve (246) has a return passage (446), for supplying thecushion member (346) with oil from the engine.
 7. An assembly accordingto claim 1, characterised in that the extension (111) has, at the levelof the bearing means (346), a radially projecting local portion (211).8. An assembly according to claim 7, characterised in that theprojecting portion (211) constitutes the free end of the crankshaft (11)and has a nose (311) for centring the clutch flywheel.
 9. An assemblyaccording to claim 7, characterised in that the flywheel (13), equippedwith a rotor (6) of the rotary electrical machine (2), is fixed on theprojecting portion (211) at the end of the latter.
 10. An assemblyaccording to claim 1, characterised in that the sleeve (246) penetrates,with clearances, into a cavity of the flywheel (13) delimited by a firstportion (46) having an axially oriented surface for mounting thereon therotor (6) of the rotary electrical machine (2), and by a second portionfor fastening the flywheel on the extension (111).